Tincalconite

Formula: Na₂B₄O₅(OH)₄.3H₂O

Origin of name: from Sanskrit tincal = borax and Greek konos for powder in allusion to the minerals composition and appearance

Crystal system: Hexagonal

Crystal class: 32

Twinning:

Unit cell: a = 11.097, c = 21.114

Colour: Colourless to white

Diaphaneity: Translucent to opaque

Luster: Vitreous to dull

Habit: fine-grained powder, rare crystals are pseudo-octahedral

Hardness:  2

Specific gravity: 1.88

Cleavage: 

Tenacity: 

Streak: White

Synonyms/varieties:

Comments:  Formed through dehydration of borax or other Na borates.